https://github.com/molefrog/use-leader

🙋‍♀️ React hook for cross-tab leader election
https://github.com/molefrog/use-leader

distributed-systems hook leader leader-election reactjs

Last synced: 8 days ago
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🙋‍♀️ React hook for cross-tab leader election

• Host: GitHub
• URL: https://github.com/molefrog/use-leader
• Owner: molefrog
• License: mit
• Created: 2023-02-27T13:13:31.000Z (over 1 year ago)
• Default Branch: main
• Last Pushed: 2023-05-23T11:03:28.000Z (over 1 year ago)
• Last Synced: 2024-11-01T13:51:44.387Z (15 days ago)
• Topics: distributed-systems, hook, leader, leader-election, reactjs
• Language: TypeScript
• Homepage: https://use-leader.surge.sh
• Size: 150 KB
• Stars: 16
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
```js

/**

 *  `useLeader()` – React hook that checks whether the current tab is the primary one.

 *  works over `BroadcastChannel` and uses slightly modified "Bully" leader election.

 */

// simple usage

import { useLeader } from "use-leader"

const { isLeader } = useLeader() // true/false

// alias, provides boolean value only

import { useIsLeader } from "use-leader"

const isLeader = useIsLeader() // true/false

// additional state 

const { 

  id,       // id of the current node (tab)

  leaderId, // id of the elected leader

  ref       // reference to election instance, can be used for imperative control

            // over the state of the node e.g. `ref.lead()` - force become a leader

} = useLeader()

// each node has a unique identifier, when the leader is elected, every node holds 

// the leading id. these ids are randomly generated... so why would you want 

// to override it?

const { isLeader } = useLeader({ id: 'my1d' })

// the answer is instance sharing. if your app has two places where `useLeader()` 

// is called, they both have access to the same node instance.

   // useLeader() - true, id = "abc"

   // useLeader() - true, id = "abc"

 // useLeader({ id: "efg" }) - false, id = "efg"

// when all components that rely on `useLeader()` exit the tree, the node shuts down,

// meaning that the other tabs now can take the advantage and relect the leader

// "totalitarian" mode (`true` by default) means that when a new node enters the quorum, 

// the existing leader won't give up power even if the new node's id is higher.

useLeader({ totalitarian: false })

// see website https://use-leader.surge.sh/ for interactive demos

```